The present invention deals generally with marking devices and more specifically with revolving printing devices which are used for marking packages, labels and the like.
Before manufactured goods reach an ultimate user, they are passed through a number of intermediate handlers, including wholesale distributors, retail distributors and various shipping and freight companies. Each handler generally is responsible for the goods while it is in his possession and often utilize a marking system for identifying goods as they are received. The marking system may also serve the function of identifying goods that have been handled by particular personnel within a company for the purpose of internal control over work quality.
In a typical marking system, the packages to be marked pass along a conveyor belt and are marked by an apparatus which is mounted at the side of the conveyor belt. Conventional marking devices of this type employ a revolving printer wheel and a revolving inking wheel in contact with the printer wheel. The printer wheel and inking wheel are mounted on a single arm which is in turn pivotally mounted on a vertical shaft at the side of the conveyor belt. The device prints a coded message contained on the printer wheel when the lateral side of the box makes frictional contact with the printer wheel. The arm of the device is generally spring loaded to urge the wheel against the side of the box to ensure sufficient pressure for printing. Other similar devices for marking the tops of packages are also available. Top marking devices are mounted on a horizontal arm positioned above the package to be printed. Both system have proven to be quite effective for marking boxes of a uniform size. However, problems have been encountered when boxes of multiple sizes and weights are passed along a single conveyor system. The problems result due to the fact that the surfaces of the packages to be marked are positioned at varying distances from the pivot arm of the marker. This difference in distances causes problems with the printer wheels making contact with the box and also causes problems with the printing pressure to be applied to a box after contact is made. The bottom mounted device of the present invention solves these problems.
In some applications existing marking systems are not desirable for ascetic reasons. In these situations, it would improve the appearance of the package to mark it on the bottom, rather than the top or side. The most convenient place for mounting a bottom marking device would be the space between two conveyor belts. However, space requirements of present marking systems generally make such mounting unpractical.
From the above it may be seen that a need exists for an improved marking device capable of printing on the bottom of packages. The device should be able to mark packages as they are transferred between conveyor belts. The system should also be capable of marking boxes of varying sizes and weights. Finally, the system should be of a narrow width to accomodate limited space requirements and should be easily removable for re-inking and routine maintenance.